With the development of communication industries, RFID technology has been widely applied in more and more fields. Radio frequency identification technology is a wireless communication technology with which a specific object may be identified and related data may be read and written based on a radio signal, without establishing a mechanical contact or an optical contact between an identification system and the specific object.
The RFID technology is applied in many industries. For example, a tag is attached onto a car being produced, and the factory party may track the progress of the car on the production line. The position of a drug may be tracked in a warehouse. A radio frequency tag may be attached to livestock and pets, allowing the livestock and pets to be positively identified (“positively identified” means to avoid that several animals use the same identify). An identification card based on RFID technology may allow an employee to enter a locked building, and a radio frequency transponder in a car may be used for paying fees related to toll road and parking, for example.
For portable electronic devices, such as a point-of-sales (POS) device, sometimes it is necessary to cover a safety protection device with resin or package the safety protection device, which results in the structure of the safety protection device being heavier and thicker. Therefore, an RFID antenna is widely used in the field of POS devices, to increase an internal space to accommodate more components, thereby making the POS device smaller and lighter.
FIG. 1 shows a manufacturing process of an RFID antenna using conventional technology. The base material 1 is a flexible base material of 250 mm×320 mm, from which eight RFID antenna substrates 2 are cut. A helical coil of a conductor forming a layer on the antenna substrate 2 is formed by means of printing or etching to form a helical antenna. The conductors may be copper traces or other conductive traces. Ends of the conductor occur at an inner periphery and at an outer periphery. Since the end at the inner periphery of the antenna needs to be led to the outer periphery so that the two ends are connected together to other ports, through holes are arranged on the substrate to connect conductively the inner periphery to the outer periphery. Hence, the flexible base material must be a double-sided base material, that is, conductive lines may be arranged on both sides of the base material, which increases the cost and complicates the production process. In addition, this manner of making the antenna is not an efficient use of the material due to the high percentage of discarded material. This further increases the cost of the POS device.